Sports Betting Glossary

Action: The total amount of money wagered on a game or event, or the money one person has on the outcome of an event. See also: Handle.

Action Reverse: A type of bet that combines two "if" bets. Both "if" bets must win for the action reverse to be successful.

Arbitrage: Simultaneously betting on all possible outcomes of a game or event to guarantee a profit regardless of the result.

Back: To bet on an outcome to happen, typically used in exchange betting.

Backer: A person who places bets on an outcome to happen, typically used in exchange betting.

Bad Beat: A loss that is perceived as particularly unfair or unlucky due to unusual circumstances.

Banker: A bet considered to have a high probability of winning, often used in parlay bets.

Bankroll: The amount of money a bettor has set aside for betting purposes.

Beard: A person who places bets on behalf of someone else to conceal the identity of the true bettor.

Betting Exchange: A platform where bettors can bet against each other, with the exchange taking a commission on winning bets.

Bettor: A person who places bets on sporting events or other outcomes.

Book: Another term for a bookmaker or sportsbook.

Bookie: Informal term for a bookmaker.

Bookmaker: An individual or organization that accepts and pays off bets on sporting events. See also: Sportsbook.

Breakeven Percentage: The win rate you must achieve on bets at a given set of odds to avoid losing money long-term. It’s calculated by dividing the risk by the total potential return (risk + reward).

Buy Points: Paying extra to adjust the point spread or total in your favor.

Card: A list of betting opportunities provided by a sportsbook for a particular day or event.

Cash Out: A feature offered by some sportsbooks that allows bettors to settle their bet early for a reduced payout before the event concludes.

Chalk: A significantly favored side in a game.

Closing Line: The final betting odds offered by bookmakers just before an event begins.

Closing Line Value (CLV): The difference between the final betting line and the line at which a bettor placed their wager.

Correlation: A measure (between -1 and 1) of how two variables move together. Positive correlation means they increase together; negative means one goes up while the other goes down.

Correlated Parlay: A parlay bet where the outcome of one selection affects the outcome of another.

Cover: When a team or selection beats the point spread.

Data Science: The practice of turning raw data into insights using math, statistics, programming, and domain knowledge. In sports betting, it means using data to understand odds, predict outcomes, and find edges.

Dead Heat: When two or more selections finish a race or event in a tie, resulting in reduced payouts.

Decimal Odds: Betting odds expressed as a decimal, commonly used in Europe and Australia.

Degen: Slang term for a reckless or compulsive gambler.

Derivative (Bet): A wager whose price is based on, or derived from, the main betting line for a game. Examples include first-quarter spreads, team totals, or alternate lines.

Dime: A $1,000 bet.

Dog: Short for "underdog," referring to the side expected to lose.

Dollar: A $100 bet.

Double Result: A type of bet where the bettor predicts both the halftime result and the full-time result of a game or event.

Edge: A perceived advantage or insight that gives a bettor an increased chance of winning.

Even Money: A bet with odds of 1:1, +100, or 2.00 where the potential winnings equal the amount wagered. Also written as EV.

Exotic Wager: Any bet other than a straight bet or parlay, often involving multiple variables or outcomes.

Expected Value (EV): The long-term average profit or loss you can expect on a bet, calculated by multiplying each possible outcome by its probability and summing the results.

Favorite: The side expected to win.

Fixed Odds: Betting odds that are agreed upon at the time the bet is placed and do not change.

Fractional Odds: Betting odds expressed as a fraction.

Futures Bet: Placing a wager on the outcome of an event that will occur in the future.

Gambler's Fallacy: The mistaken belief that previous outcomes affect future outcomes in games of chance.

Handicapping: Analyzing and predicting the outcome of sporting events, often involving factors such as injuries, weather conditions, and team statistics.

Handle: The total amount of money wagered by bettors on a particular event or over a specific period. See also: Action.

Hedge: Placing bets on the opposite side of an initial wager to reduce potential losses and/or guarantee a profit.

Hook: Half a point added to point spreads to prevent ties, often written as ".5" (e.g., 3.5 points).

In-Play Betting: Another term for live betting, where wagers are placed during the course of a game or event.

Juice: Another term for vigorish, representing the bookmaker's theoretical commission on a bet.

Lay Bet: Betting on an outcome not to happen, acting as the bookmaker.

Layoff: Placing bets with other bookmakers to balance the risk of large wagers.

Limit: The maximum amount a sportsbook will accept on a single bet.

Line Movement: Changes in the odds or point spread offered by bookmakers due to betting activity.

Live Betting: Placing bets on a game or event while it is in progress. See also: In-play betting.

Lock: A bet that is considered to be guaranteed to win, often used informally to describe a highly confident wager.

Long Shot: A bet with very low odds of winning, often associated with high potential payouts.

Market Efficiency: A measure of how accurately betting odds reflect the true probabilities of outcomes. In an efficient market, lines adjust quickly to new information and leave little room for profitable bets. In less efficient markets, odds may be slow, mispriced, or exploitable.

Middle: A betting strategy where a bettor places wagers on both sides of a game or event, hoping the final margin falls within a specific range to win both bets.

Model: A mathematical or statistical framework used to estimate the probability of sports outcomes and identify value bets.

Moneyline: A bet on which team will win a game outright, regardless of the point spread.

Nickel: A $500 bet.

Noise: Random or irrelevant information that looks like it matters but doesn’t actually help predict outcomes. In betting, this could be hot takes, small-sample stats, or meaningless trends.

Novelty Bet: A bet placed on non-sporting events or outcomes, such as political elections or entertainment awards.

Martingale: A betting strategy where the bettor doubles their stake after each loss, aiming to recoup previous losses with a single win.

Offshore Sportsbook: A sports betting site or establishment located outside the jurisdiction of the United States.

Odds: The probability of a particular outcome occurring, typically represented in American, decimal, or fractional format.

Off the Board: An event temporarily unavailable for betting at a sportsbook, typically due to uncertainty or significant variables impacting the outcome.

Opening Line: The initial point spread or odds set by bookmakers for an event.

Outright Bet: A wager placed on the winner of an entire tournament or competition, rather than individual matches or games.

Over/Under: A bet on whether the total score of a game will be over or under a specified number.

Parimutuel Betting: A system of betting where all bets of a particular type are placed together in a pool, with the winnings divided among the winning bets after deductions.

Parlay: A single bet that links together two or more individual bets for a higher payout.

Pick: A selection made by a bettor for a particular game or event.

Pick'em: A game or bet where neither side is favored, typically with a point spread of zero. Often written as “pk”.

Plus Money: Another term for positive odds, indicating the potential profit is greater than the amount wagered.

Point Spread: A margin of points set by bookmakers to even the odds between two teams.

Prop Bet (Proposition Bet): A wager on specific outcomes or events within a game or event that are not directly related to the final score.

Punter: A bettor, particularly in the UK and Australia.

Push: When the result of a bet falls exactly on the point spread or total, resulting in a tie or refund.

Push Rate: The percentage of bets that land exactly on the posted line, resulting in a “push” (no win, no loss, stake returned). Tracking push rate matters because it affects the true value of spreads and totals.

Python: A popular programming language known for being beginner-friendly and powerful. Widely used in betting, modeling, and AI because of its math and data libraries.

Quant: Short for “quantitative analyst.” Someone who uses math, statistics, and data models to make decisions. In betting, a quant builds models to price games and spot edges rather than relying on intuition.

R: A programming language built for statistics and data visualization. It’s especially strong in running models, exploring data, and creating graphs.

R-Squared (R²): A number between 0 and 1 that shows how much of the variation in the outcome your model explains. Higher values mean your predictors fit the data better.

Regression: A statistical method used to estimate the relationship between one outcome (like points scored) and one or more predictors (like shooting %, pace, or opponent strength).

Residuals: The differences between what your model predicted and what actually happened. Analyzing residuals helps check how well your model works.

Return: The total amount of money a bettor receives if their bet is successful, including the original stake and any winnings.

Rollover: The number of times a bettor must wager their deposit or bonus funds before being able to withdraw winnings.

Round Robin: A type of bet that combines multiple parlays on a group of selections, resulting in a series of smaller bets.

Run Line: A type of point spread bet used in baseball, where the favored team must win by a certain number of runs or the underdog must lose by fewer runs than the spread.

Sharp: A professional or knowledgeable bettor who consistently makes well-informed wagers. See also: Wise Guy.

Signal: The useful information that truly explains or predicts outcomes. In betting, signal might come from reliable stats, market movement, or proven models that consistently add predictive value.

Sportsbook: A facility, website, or establishment that accepts bets on sporting events. See also: Bookmaker.

Square: An inexperienced or casual bettor who typically bets for entertainment rather than profit.

Stake: The amount of money wagered on a single bet. See also: Wager.

Steam: Rapid and significant line movement across multiple sportsbooks, usually due to heavy betting activity by sharps.

Straight Bet: A single bet placed on a single outcome, also known as a "straight wager" or "single bet."

Syndicate: A syndicate is a group of bettors who pool their money, resources, and expertise to wager collectively. Syndicates often use advanced models, information networks, or specialized roles (data collection, modeling, execution) to gain an edge over sportsbooks.

Synthetic Line: The effective “fair” price you get by combining the best sides of related markets or different sportsbooks to create a near-zero-hold synthetic market (the line implied by that combo).

Tipster: Someone who provides betting tips or predictions, often for a fee or tips in exchange.

Teaser: A type of bet that allows the bettor to adjust the point spread or total in their favor for reduced odds.

Tout: Someone who sells or promotes their expertise in sports betting picks or predictions.

Unit: A standardized measurement used by bettors to quantify the size of their wagers relative to their bankroll.

Value: A bet that is deemed to have favorable odds compared to the perceived probability of the outcome occurring.

Variance: A measure of how spread out results are from the average. In betting, higher variance means results swing more wildly (big wins and losses), while lower variance means outcomes stay closer to expectations.

Vigorish (Vig): The theoretical commission that a bookmaker charges for accepting a bet.

Wager: The amount of money placed on a bet.

Wise Guy: Another term for a sharp or professional bettor. See also: Sharp.